[PATCH] tmpfs work update 013010 (was tmpfs initial work)
naoya.sugioka at gmail.com
Mon Feb 1 20:27:11 PST 2010
I'm glad you are happy with my porting & implementation.
Always you do patching and running then let me know any issues you
Any comments always give me a new or different sight for the current
If the comment comes from experts like you, that motivates me (and
others) a lot.
Once more thing, I wonder I should migrate my dev environment to x64
from current i386
to catch atoi() like issues earlier.
Does somebody know if a qemu x64 emulator works on the DragonFly/x64 host ?
(Now I do (k)qemu i386 on DragonFly/i386.)
On Sun, Jan 31, 2010 at 6:43 PM, Matthew Dillon
<dillon at apollo.backplane.com> wrote:
> :Hi Matt and others,
> :Here comes 3rd iteration.
> :1) reimplement tmpfs_read(), tmpfs_write() call by following Matt's
> :2) tmpfs_strategy() is a kind of temporary hack. Just call
> :3) implement tmpfs_advlock() with lockf structure
> :The change makes tmpfs more stable (make nativekernel works on tmpfs
> ::) though, still
> :some issues. 1)An umount will hit assertion. 2)There are some cases to
> :observe non-res
> :from tmpfs too. 3)An userland command (mount_tmpfs) is no progress,
> :has a lack of features.
> :I'll start looking a new truncation/extention API beyond this change,
> :then dive into above
> :issues and items.
> :thank you, Any comments are always welcome.
> Your patch is really looking good now. Would it be too early for
> us to start testing it or should we wait a little longer?
> Here are a few things I noticed from perusing your patch:
> * case 's' for the size specification uses atoi(), which is
> limited to a 32 bit integer while ta_size_max is an off_t (64 bit).
> I recommend using strtoimax() instead of atoi().
> * I see you are using MNTK_MPSAFE. That won't apply to read,
> write, getattr, and inactive. They have their own MNTK_xx_MPSAFE
> flags which you also need to specify too if you want those VOPs to
> be MPSAFE (and you clearly do).
> * You may want to add the other MNTK_xx_MPSAFE flags but remove
> MNTK_MPSAFE for initial testing until you get things rock solid,
> then work MNTK_MPSAFE back in.
> * For tmpfs_write() I think you can safely just use bdwrite(),
> and there is no need to implement the B_CLUSTER* support (though
> it won't hurt I don't think it will improve performance much
> * Currently you are using a separate VM object for the vnode
> (via vinitvmio()) and the backing store (via tn_aobj).
> This is something that only the VN device (/usr/src/sys/dev/disk/vn)
> has done in the codebase. It should work and I think it is an
> excellent solution to the backing store issue.
> I see you even implemented the freeing of swap space in the
> truncation code. Wow! Very cool!
> I think shifting it to the new nvtruncbuf()/nvextendbuf() API will
> be trivial. It will even simplify the tmpfs code slightly.
> Again, incredible work! Please keep us posted!
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